K 2500 Truck 4WD V8-5.3L VIN T (1999)
Information Bus: Initial Inspection and Diagnostic Overview
1. Inspect for the proper connection of the scan tool to the Data Link Connector (DLC).
2. Inspect for loose or missing terminals at the DLC.
3. If the Vehicle Control Module (VCM)/Powertrain Control Module (PCM) is not accessible with a scan tool, inspect for an open in CKT 1049
(DK GRN) between the component and splice pack 205 (SP205).
4. If the Electronic Brake Control Module (EBCM) is not accessible with a scan tool, inspect for an open in CKT 1122 (LT BLU) between the
component and splice pack 205 (SP205).
5. If the body control module (BCM) is not accessible with a scan tool, inspect for an open in CKT 1037 (LT GRN) between the component and
splice pack 205 (SP205).
6. If the instrument cluster is not accessible with a scan tool, inspect for an open in CKT 1036 (GRY) between the component and splice pack 205
(SP205).
7. It the Automatic Transfer Case (ATC) control module is not accessible with a scan tool, inspect for an open in CKT 1133 (DK GRN/WHT)
between the component and splice pack 205 (SP205).
8. If the scan tool will not communicate with any module on the class 2 data line, inspect for an open in CKT 1132 (PPL) between splice pack 205
(SP205) and DLC terminal 2.
9. If the Inflatable restraint sensing diagnostic module is not accessible with a scan tool, inspect for an open in CKT 800 (TAN) between the
component and the DLC terminal 9.
10. Inspect for the proper installation of the aftermarket electronic equipment that may affect the integrity of the other systems.
11. Inspect for a broken, or partially broken, wire inside of the insulation. A broken, or partially broken, wire could cause the system to malfunction
but prove good in a continuity/voltage test with the system disconnected. The circuits may be intermittent or resistive when loaded. If possible,
inspect the circuits by monitoring for a voltage drop with the system operation (under load).
